Topic: Pneumonia.

What causes pneumonia?

The letter P. No.

Pneumonia is a lung infection caused by microorganisms which generally leads to difficulty in breathing.

Normally, we inhale oxygen rich air which reaches our alveoli.

Alveoli are surrounded by blood capillaries.

Here, the oxygen through the walls of alveoli diffuses into our blood.

However, sometimes we also inhale harmful microorganisms.

Mostly, the cilia and mucous in our respiratory tract trap these microorganisms, which are then expelled while coughing.

But sometimes the microorganisms don't get trapped and reach the alveoli.

There they start to multiply, causing lung infection, that is, pneumonia.

No.

Now what to do?

Now, to protect ourselves, the immune cells start attacking the microorganisms, causing inflammation and accumulation of fluid in the alveoli.

As a result, the inhaled oxygen cannot get easily diffused into blood, thus causing difficulty in breathing.

Topic: Dandruff.

Why do we get dandruff?

Tearing of pages.

No.

Dandruff is a condition in which our scalp sheds skin cells in the form of white flakes.

A yeast called Malassezia globosa, is one of the mostly accepted reasons for causing dandruff.

Wow.

What a classy name it has.

Indeed.

Malassezia globosa is naturally present on our scalp.

It feeds on sebum and releases oleic acid.

Now, some people are sensitive to this oleic acid.

When it penetrates the upper layers of their skin, it causes inflammation.

Hence, in response to this inflammation, their skin sheds a large number of skin cells at a higher rate.

These cells then join together forming white flakes, thus causing dandruff.

Topic: Joints.

Why do knuckles pop?

So that when we get bored we can pop them for time pass.

No.

A knuckle is a joint in the finger where two bones come together or connect.

This joint is filled with a fluid called synovial fluid.

Synovial fluid is a viscous fluid containing dissolved gases like oxygen and carbon dioxide.

When bones move, the synovial fluid prevents them from grinding against each other.

Wow.

It is so amazing.

Indeed.

When we stretch or bend our finger, the space between the two bones increases.

This causes the synovial fluid to stretch, thus creating low pressure in it.

Now, as gases are less soluble at low pressure, the dissolved gases in the synovial fluid undissolve, resulting in the formation of a bubble, which we hear as the pop sound.

Topic: Anaerobic respiration.

What is the cause of muscle cramps?

Excess sleep.

No.

Respiration is a process in which the cells of our body produce energy.

Normally, our cells respire aerobically.

In this process, the glucose with the help of oxygen is completely broken down to produce energy, water and carbon dioxide.

Is this energy then used for all our activities?

Indeed.

However, during heavy exercise, our body cannot deliver enough oxygen to the cells of our muscles.

Hence, in such situations anaerobic respiration helps us to produce some energy temporarily and thus, continue our work.

In anaerobic respiration, the glucose is partially broken down in the absence of oxygen to produce comparatively less amount of energy and a waste product called lactic acid.

Now, one of the most prominent reasons for the muscle cramps is the accumulation of this lactic acid.

Topic: Sinkholes.

What causes sinkholes?

Maybe water.

This time you are absolutely correct.

Yes.

A sinkhole is a depression or cavity in the ground which is caused by water erosion.

Water erosion is a naturally occurring process in which water wears off soil and rocks.

Wow.

Water is so powerful.

Indeed.

Now listen.

The upper layers of the soil comprise of sand, clay, etc.

While the bottommost layer called bedrock has rocks.

Generally, sinkholes form in places where the bedrock layer has rocks made up of limestone or dolomite.

When rain falls, it seeps into the soil reaching the bedrock.

Over time, the water dissolves these rocks and thus, erodes them forming hollow cavities.

As these cavities get bigger, the ceiling of the cavity, that is, the upper layers of soil cannot hold the weight, hence they collapse forming sinkholes.

Topic: Human Nose.

Why do we get nosebleeds?

I don't know.

Alright.

I will explain.

The medical term for a nosebleed is epistaxis.

The most common epistaxis is anterior epistaxis where bleeding happens from the front part of our nostrils.

Each of our nostrils has a mass of blood vessels called Kiesselbach's plexus which is very close to the skin surface.

Now, usually the mucus moisturizes the skin in our nose, thus protecting the blood vessels in it.

Wow.

Mucus is so useful.

Yes.

It is.

However during winter, the air is dry.

Hence, when we inhale this dry air, it draws moisture from the mucus which in turn leads to the drying of skin in our nose.

Now, some people's skin is very sensitive.

If it dries, the skin and blood vessels in it get easily damaged causing an anterior epistaxis or nosebleed.

Topic: Vaccines.

How do vaccines work?

By giving extreme pain.

Not at all.

Vaccines train our body to fight against the dangerous disease causing pathogens.

Oh really.

Do they have a training academy?

You are just unbelievable.

Vaccines often contain weakened or dead pathogens.

When they are injected into our body, they just trigger the immune response but do not cause fully fledged diseases.

Our immune cells recognize these pathogens as foreign invaders and thus, produce antibodies.

These antibodies kill the pathogens.

Also, the immune cells record the information about the pathogens and the way they were killed.

Hence, in case in the future, a similar strong pathogen enters our body, our immune cells remember and easily identify that pathogen.

They produce the required antibodies to fight it back.

Thus, we remain healthy.

Topic: Cheese.

Why does Swiss cheese have holes?

Those are not holes.

They are eyes of the cheese.

No.

Cheese is made from milk.

Milk contains a sugar called lactose which is very important in the formation of cheese.

Now while making Swiss cheese, bacteria like S. Thermophilus, Lactobacillus and P. Shermani are added to milk.

What?

Bacteria are added to milk?

Absolutely.

However, they are good bacteria.

Out of these bacteria, the S. Thermophilus and Lactobacillus first convert the lactose into lactic acid, producing curd.

Then after undergoing certain processes, when the curd is kept for maturing, the P. Shermani bacteria consumes the lactic acid and releases carbon dioxide gas.

Being trapped, the carbon dioxide gas forms bubbles.

Eventually, when we cut the cheese, the bubbles pop, resulting in holes in the Swiss cheese.

Topic: Chapped lips.

What causes chapped lips?

Making weird faces.

No.

Our lips are very sensitive.

This is because the outermost layer of our skin called stratum corneum is much thinner on our lips than on any other body parts.

As it is thinner, the blood vessels inside them are more prominent making our lips appear reddish or pinkish.

Besides this, the skin on our lips doesn't have oil and sweat glands which secrete substances to moisturize the lips.

Hence, our lips have very less moisture.

Now, usually during cold months, as the air has less moisture, the moisture from our lips evaporates causing them to get dry and chapped.

So to provide moisture, we can lick our lips and apply saliva.

No.

Saliva draws more moisture and heat from our lips and evaporates, thus leaving our lips more drier than before and thus, making the condition worse.

Topic: Pins and needles.

Why do limbs fall asleep?

Because they are tired.

No.

It basically happens because of nerves.

Through nerves, our brain communicates with our limbs.

Nerves are so amazing.

Yes.

However, when we cross our legs or sleep on an arm for very long, we apply pressure causing the nerve pathways and its surrounding arteries to squeeze.

Hence, the nerves do not work properly and the arteries cannot supply required nutrients to the nerves.

As a result, the signals sent by our brain do not reach the limb.

Thus, we cannot move it.

So, we say that our limb has fallen asleep.

Also, in some situations, some of these squeezed nerves stop sending signals while some fire hyperactively.

This gives us the sensation of pins and needles.

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